Automatic mechanism for carbines



Febzz, 1949. RRUDD 2,462,313@

AUTOMATIC MECHANISM FOR CARBINES Filed Feb. 27, 1947 y 4 2 Sheets-Sheetl Feb, z2, 1949. I R. RUDD mams@ AUTOMATIC MECHANISM FOR GARBINESFileg'Feu 27, 1947 2 sheets-Sheet 2 H E5 .5- D o 4 A. E? J Y z 28 ,$4 439' \O RDBB'RUCI Patented Feb. 22, 1949 3 Claims.

(Granted under the act of March 3 188.3, as;

amended Apr1i30 1928;. 370 0. G. 75.7)

Theinvention described in the following speci'- fication and claims maybemanufactured; and used by or for the Government for governmentalpurposes without the payment to me of any royalty thereon.

This invention relates to a new and useful mechanism for automaticoperation oi carbines and is particularly designed to modify a carbine,cal. .30 whereby it can be fired either iull auto matic orsemi-automatic. The device is very simple in construction and operation,comprising only few parts which are readily fabricated and attached bymaking very slight changes in the firing mechanism of' the Carbine. Oneof the most important advantages of the device is that all carbinesalready in use can be easily and quickly converted with no maior changesin the standard mechanism. The modied gun contains only. two additionaloperating parts, a cam plate and a. trigger bar, both of which are madefrom flat material suitable for easy and rapid production. The otherparts are a stud, springs and pins of ordinary types. The onlymodification of. the firing mechanism is bores -ior the stud and. pins,and slots for the plate and bar.

The cam plate is pivotedin the trigger to operate the sear, forautomatic tiring. The trigger bar is mounted on the trigger housing foroperating the cam plate. The stud is adjustable on the operating slideof the Carbine for operating the trigger bar automatically by action ofthe slide.

The device is so designed that it can be applied. to the Carbine andthen rendered operative for full automatic iire or rendered inoperativefor semi-automatic iire. Thetwo conditions of the device depend merelyon the adjustment of the stud relative to the operating slide. When thedevice is inoperative, the firing mechanism functions for semi-automaticre in its normal manner unaffected by the attached device. It is obvioustherefore that any failure of the device will not affect thesemi-automatic operation of the Carbine, which is one of the distinctadvantages of the device.

While one specic embodiment of the invention is illustrated in thedrawings and hereinafter fully described, it is to be distinctlyunderstood that the invention is not considered to be limited to saidspecific embodiment but that its scope is defined by the claims appendedhereto.

In the drawings:

Figure 1 is a side elevation of the ring mechanism of a carbine equippedwith the device, the

2 parts.beingiinnormal;position;ionsemieautomatic operation;

Figure.v 2; is@ al longitudinal, axial, verticaly sec'- tioircfythemechanism shown in Figure i;

Figure 3i is a: fragmentaryv section or' triggen, scar anouhamrner4 of"Figure 2; theparts beingrin cocked. position, for semi-automaticoperation;

Figure 4 isarview similari to Figure, thefparts` being cockedA forautomatic operation;`

Figure-5 is a2 View similarto Figure 2, showingthe automatic operationreleasing thehammer from its position in- Figurel for firing;

Figure Gis a perspective viewof` the y device".

sociated with'the trigger; sear, hammer and frag'- ment of theoperatingy slide; l

Figure '7A is a longitudinal verticalI sectionV of' the trigger;

Figure isa perspective view'oi the cam plate ofthe device for the'automatic operation oflthe scar;

Figure 9 isa -,fragmentaryside elevation'o-ithc modified operatingslide,partly-insection;

As illustrated in the drawings; the device is applied` to a U.' Sicarbine, cal. .30' havingthe iiring mechanism comprising theoperatingslide i` retracted by gas pressure and returned on' countenrecoilby itsspring (notshownl, thebolt 2 with 'ring pin 3; andihammer i pivotedinthe' trigger housing iwithtrigger ti andsear l'also pivoted therein.The'sear i is disposed between ears 8 on the upper edge of the trigger6.. A

pintle pin 9.', received through ears 81 ci" trigger and an elongatedslotl'll' insear 'land mountedin housing 5; pivotally mounts trigger,Yii in. housing 5; andv sear l' in trigger S". is seated in trigger 6,bears against dependingklug l2 disposed on thebottom oisear lbelowlslot. iii, andv biasesv Sear lrforwardly on pin 91 the forward armi3 of Sear ijbeing urged upwardly, Trigger fi. has in. its upperv rear.face, a slot le on each,

side. of. which are sockets. i5, respectively, to re.- ceive. the endsof' the trigger spring iii mounted in housing. 5. and biasing trigger 6.forwardly, into.

inoperative position. Trigger. 6 has a forwardly projectedsaiety noselil' cofacting withal sliding safety bolt Edin housing. 5. and, having aslot iii.

into :whichnose Il is received when the safety4 bolt t8. is oscillatedvto, permit ring. Trigger has a shoulder 2i)` on its rear facecomet-ingfwith.

housing 5to-limit. rearward vmovement of triggeri 6. Trigger. @has apair ofl-upstanding ears 2l to co-actwith rear arm.2.2of.sear 'l for.Ysemi-auto.- i TheI hammer, il.: is. pivoted on matic. operation.

pintlelpinl @amounted in housing' so; th at ywhen its head 24" is swungiforwardly it co-acts with A. scar spring.;v l 1."

firing pin 3 when bolt 2 is in battery. Head 24 has a cam shoulder 25co-acting with bolt 2 to swing head 24 rearwardly to cock hammer 4.Hammer 4 has a convex bottom enge 2c against which forward aim I3 ofsear l bears, and a notch 2'I a-t the rear end of edge 25 into which theouter end of forward arm |3 is received when the hammer 4 is cocked.Hammer 4 has an operating plunger 28 mounted in the housing 5 and urgedforwardly by the hammer spring 23', to

cause head 24 to impinge against ring pin 3 when hammer 4 is releasedfrom sear ll.

The improved device, by which the above described details ofconstruction are modified for automatic operation, comprises anoperating cam plate 29 for actuating sear 'I to release hammer 4, atrigger bar 3|) yforactuating the plate 29, a selector stud 3| foractuating the trigger bar 99 and a stop-pin 32 for limiting movement ofplate 29.

The plate 29 is disposed in slot I4 of trigger 6, being pivoted intrigger 6 by pintle pin 33 in trigger 6. Plate 29 has a cam shoulder 34coacting with rear arm 22 of sear and a head 35 projected upwardly atthe rear of plate 29. The trigger bar 30 is slidably mounted on housingby means of a headed pin 36, the shank of which passes through anelongated slot 31 in the said bar and is welded to the trigger housing5. Bar 30 has on its rear end an operating finger 38 received in a slot39 in housing 5 and .co-acting with head 35 of plate 29 to rock plate.29 forwardly when bar 30 is oscillated forwardly. Bar 30 has on itsfront end an upwardly extended operating post 40 with which co-acts theselector stud 3| which is vertically slidable in the rear end of theoperating slide I. As clearly shown in Fig. 9, the stud 3| is receivedin a suitable bore 4| in slide I, with depressions 42 for spring pressedbutton 43 for retaining stud 3| in adjusted positions. Stud 3| ismounted in slide immediately adjacent retracting handle 44 for manualmovement of slide I. It will be understood (Fig. 6) that when stud 3| isdepressed to extend below slide it engages post 40 to slide bar 3|)forwardly, and that when stud 3| is raised to extend above slide I byplacing a finger under the stud and pressing it upward (Fig. 1) the stud3| passes above the top of post 40. The trigger bar 30 has a shoulder 45against which bears an expansion spring 46 mounted in housing 5 forsliding bar 30 rearwardly when spring 45 is tensioned by forwardmovement of bar 39. Pin 32 is mounted in housing 5 rearwardly of plate29 to limit rearward movement of plate 29 to properly relate head 35 ofplate 29 and finger 38 of bar 30.

From the foregoing description of the details of construction of thedevice and its application to the firing mechanism of the carbine, itsuse and operation will be obvious. Figures 1, 2 and 3 show the device ininoperative position, thereby conditioning the Carbine forsemi-automatic operation. To render the device inoperative the selectorstud 3| is raised (Fig. 1) The parts being as shown in Figure 2 (normalposition), the operating slide is retracted by pulling the retractinghandle 44, thereby retracting bolt 2 to cock hammer 4, feed a round fromthe magazine into loading position, and `tension the spring of slide I.When the slide I is released, its spring projects the slide I and bolt 2to battery, chambering the round. As shown in Figure 3, the sear 'Ihaving its forward end I3 seated in notch 2`I of hammer 4 is retractedon pin 9 bythe force 4 of the tensioned hammer spring 28. superior tothat of sear spring |I, its rear arm 22 being disposed on top of ears 2|which are depressed by trigger 6 disposed forwardly in inoperativeposition. When safety bolt I8 is shifted to permit nose I'I to enterslot I9, the carbine can be fired. When trigger 6 is squeezed, it rockson pin 9 to raise ears 2| which raise arm 22 to rock sear I releasinghammer 4 which functions to re the chambered round. The recoil of slideand bolt 2, ejects the case of the red round, cocks hammer 4, and feedsthe second round to loading position. Counter recoil chambers the secondround and brings the slide I and bolt 2 to battery, and the carbine isconditioned to be rered by trigger 6 which, released after first roundwas fired, has returned to normal inoperative position. It will:be'noted (Figs. 2, 3 and 4) that during the above-described operations,nger 38 is held fully retracted and plate 29 is slidably supported bystop-pin 32, and has no part in the semi-automatic operation.

Figures 4, 5 and show the device in operative position therebyconditioning the Carbine,y for automatic operation, To render the device0perative, the selector stud 3| is depressed (Figs. 5 and 6). The rstround is fired, as above d escribed. The trigger 6 is not released butheld retracted as shown in Figure 4. As above described, recoil ejectsthe case of the fired round, cocks hammer 4 and feeds the second roundto loading position. It Will be noted (Fig. 4) that when hammer 4 iscocked the rear arm 22 is moved against ears 2| in line with arm 22 andnot below as previously described. Sear spring Il urging arm I3 of sear'I upwardly maintains hammer 4 cocked.. Counter recoil chambers thesecond round and brings slide I and bolt 2 to battery. After themechanism for rotating bolt 2 for locking has functioned, slide movesforwardly sufiiciently (Fig. 5) to cause stud 3| to engage post '4D andslide trigger bar 30 forwardly, thereby drawing finger 38 against head35, rocking plate 29 which was raised by retraction of the trigger topressv shoulder 34 against arm 22 of sear 'l releasing hammer 4 whichfires the second round. It is obvious that this automatic operationcontinues until the magazine is exhausted or the trigger 6 is releasedto lower plate 29 and ears 2| thereby moving head 35 of plate 29 outofthe path of finger 38 (Fig. 3).

From the foregoing description of the opera.- tion. of a Carbineequipped with the improved device, it is obvious that the structuralelements, whereby full automatic operation is provided, can` beincorporated in the ring mechanism. of the Carbine -in such a manner asto dispensewith any,V

adjustability, to produce a carbine designed for full automaticre only.This can bedone ,by merely mounting stud 3| non-adiustably on the slideas by making it integral therewith.

Having described the invention, what I claim 1s:

ljIn an attachment for the 'firing mechanism of a gun whereby saidm-echanisrncan b'eoper'ated alternatively for semi-automaticandffull'a'utomatic fire, said mechanism comprising a trigger housing, atrigger pivoted in saidhousing,`"a ham;

mer pivoted in said housing, a sear pivoted in said trigger for holdingsaid hammer cocked, al slidable bolt having a ring pin therein, andanoperating slide for sliding lsaid bolt, reciprocable on recoil andcounter-recoil, the combination of a cam plate pivoted in said housingand having a cam shouldervand an upstanding head; a trig.

5 ger bar slidably mounted on said housing, having an operating nger onits rear end and a post on its forward end, and spring-biasedrearwardly; and a stud adjustably mounted in sa-id operating slide foroperative and inoperative positions to condition the mechanism for fullautomatic and semi-automatic nre, respectively, the parts being sorelated that the hammer is cocked by the bolt on recoil of said slide,and when said stud is adjusted to inoperative position, forsemi-automatic iire, the cocked hammer is released to impinge againstsaid ring pin by releasing the sear by squeezing the trigger, and that,when said stud is adjusted to operative position for full automatic re,on counter-recoil of said slide the stud contacts said post, slidingsaid bar forwardly, the forwardly moving finger of said bar, contactingsaid head of said cam plate, rocks said plate, said cam shoulder of theplate rocks the Sear, and said hammer is released to impinge againstsaid firing pin.

2. In the ring mechanism oa gun operable alternatively ior fullautomatic and semi-automatic re, the combination of sliding operatingmeans retracted on recoil and projected on counter-recoil;spring-pressed percussion ring means cocked by said operating means onrecoil; a pivoted detent for engaging said ring means; a manuallyoperated pivoted lever for rocking said detent to release said cockedring means; a second pivoted lever for rocking said detent to releasesaid-cocked ring means; a sliding member for rocking said second pivotedlever; and a second sliding member on said operating means, manuallymovable alternatively into operative and inoperative positions tocondition the mechanism for full automatic and semi-automatic re,respectively, and for sliding said rst sliding member when said secondsliding member is in operative position and said `operating means isprojected on counter-recoil.

3. In a gun, operable alternatively for full auto- 6 matic andsemi-automatic fire, the combination oi a trigger housing; atriggerpivoted in said housing; a hammer pivoted in said housing; a searpivoted in said trigger, for holding said hammer cocked; a slidable bolthaving a firing pin therein; an operating slide for sliding said bolt,reciprocable on recoil and counter-recoil; a cam plate pivoted in saidtrigger and having a cam shoulder and an upstanding head; a trigger barslidably mounted on said housing, having an operating finger on its rearend and apost on its forward end,- and spring-biased rearwardly; and astud adjustably mounted in said operating slide for operative andinoperative positions to condition the gun for full automatic andsemi-automatic re, respectively, the parts being so related that thehammer is cocked by the bolt on recoil of said slide, and when saidstudr *is adjusted to inoperative position for semi-automatic re, thecocked hammer is released to impinge against said firing pin byreleasing the sear by squeezing the trigger, and that when said stud isadjusted to operative position, for full automatic re, on counter-recoilof said slide the stud contacts said post, sliding said bar forwardly,the forwardly moving nger of said bar, contacting said head of said camplate, rocks said plate, said cam shoulder of the plate rocks the sear,and said hammer is released'to impinge against said firing pin.

ROSS RUDD.

REFERENCES CITED The following references are of record in the

